Do built-in classes have hidden properties storing "dimension information," and how can I find these hidden properties?

Do built-in classes have hidden properties storing "dimension information," and how can I find these hidden properties?

This is evidence that built-in classes property store object dimension data, which cannot be cleared even with the `empty` method.

A=double.empty(5,0);
size(A)
ans =
     5     0
     

However, I experimented with two methods and couldn't find this property that stores "dimension data."

properties(A)
没有 double 类的属性。
mc=?A

I opened mc but couldn't find any properties related to "dimension data."

Answer 1

[Walter Roberson]

It is not stored as a named property; it is stored in the fundamental descriptor along with the information such as whether the array is complex valued.

When you create your own class you can define your own size and numel methods